MAINTENANCE AND ACTIVATION OF CYP2E-1 GENE-EXPRESSION IN MOUSE HEPATOCYTES IN PRIMARY CULTURE

The expression of Cyp2e-1 mRNA and protein was investigated in the C57 BL/6NCrj mouse hepatocytes in primary culture, as well as liver and ki dney. The mRNA and protein expression in the liver was in the same ran ge in both sexes and was not affected by orchiectomy or ovariectomy. T he mRNA expression was enhanced in the kidney of ovariectomized mice, in which the protein contents were not influenced. Orchiectomy decreas ed the expression of both mRNA and protein. When the hepatocytes were transferred to primary culture, the amounts of the mRNA were not chang ed within 24 h and about half remained by day 3. However, the expressi on was low thereafter. The expression of the protein gradually decreas ed after the start of culture. Dexamethasone showed a potential as an inducer at more than 10(-8) M. Sex hormones increased the expression o f this P-450 species a little in culture, but growth hormone did not. These observations indicated that glucocorticoid hormone plays a role in modifying expression of Cyp2e-1 and that the mouse hepatocyte cultu re is useful for examining its regulation mechanism.